package com.hina.rec.common.utils;

/**
 * Created by wuchenzi on 2021/10/27.
 */

import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.pqc.legacy.math.linearalgebra.ByteUtils;
//import org.bouncycastle.pqc.math.linearalgebra.ByteUtils;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.spec.SecretKeySpec;
import java.security.*;
import java.util.Arrays;

/**
 * sm4加密算法工具类
 * @explain sm4加密、解密与加密结果验证
 *          可逆算法
 * @author Marydon
 * @creationTime 2018年7月6日上午11:46:59
 * @version 1.0
 * @since
 * @email marydon20170307@163.com
 */
public class Sm4Util {
    static {
        Security.addProvider(new BouncyCastleProvider());
    }

    private static final String ENCODING = "UTF-8";
    private static final String ALGORITHM_NAME = "SM4";
    // 加密算法/分组加密模式/分组填充方式
    // PKCS5Padding-以8个字节为一组进行分组加密
    // 定义分组加密模式使用：PKCS5Padding
    private static final String ALGORITHM_NAME_ECB_PADDING = "SM4/ECB/PKCS5Padding";
    // 128-32位16进制；256-64位16进制
    private static final int DEFAULT_KEY_SIZE = 128;
    private static final String sm4Key = "50AB3180C2806ED1F47B859DE5013DC4";

    /**
     * 生成ECB暗号
     * @explain ECB模式（电子密码本模式：Electronic codebook）
     * @param algorithmName
     *            算法名称
     * @param mode
     *            模式
     * @param key
     * @return
     * @throws Exception
     */
    private static Cipher generateEcbCipher(String algorithmName, int mode, byte[] key) throws Exception {
        Cipher cipher = Cipher.getInstance(algorithmName, BouncyCastleProvider.PROVIDER_NAME);
        Key sm4Key = new SecretKeySpec(key, ALGORITHM_NAME);
        cipher.init(mode, sm4Key);
        return cipher;
    }


    public static String stringToHex(String s) {
        // 将字符串转成16进制
        StringBuilder hexString = new StringBuilder();
        for (char c : s.toCharArray()) {
            hexString.append(String.format("%02x", (int) c));
        }

        // 获取转换后的16进制字符串
        String hexResult = hexString.toString();

        // 如果长度大于32个字符，则截取前32个字符
        if (hexResult.length() > 32) {
            return hexResult.substring(0, 32);
        }
        // 如果长度少于32个字符，则进行填充（比如填充'0'）
        while (hexResult.length() < 32) {
            hexResult = "0" + hexResult; // 在前面补零
        }
        return hexResult;
    }

/**
 * 自动生成密钥
 * @explain
 * @return
 * @throws NoSuchAlgorithmException
 * @throws NoSuchProviderException
 */
public static byte[] generateKey() throws Exception {
        return generateKey(DEFAULT_KEY_SIZE);
        }

/**
 * @explain
 * @param keySize
 * @return
 * @throws Exception
 */
public static byte[] generateKey(int keySize) throws Exception {
        KeyGenerator kg = KeyGenerator.getInstance(ALGORITHM_NAME, BouncyCastleProvider.PROVIDER_NAME);
        kg.init(keySize, new SecureRandom());
        return kg.generateKey().getEncoded();
        }

/**
 * sm4加密
 * @explain 加密模式：ECB
 *          密文长度不固定，会随着被加密字符串长度的变化而变化
 * @param hexKey
 *            16进制密钥（忽略大小写）
 * @param paramStr
 *            待加密字符串
 * @return 返回16进制的加密字符串
 * @throws Exception
 */
public static String encryptEcb(String hexKey, String paramStr) throws Exception {
        String cipherText = "";
        // 16进制字符串-->byte[]
        byte[] keyData = ByteUtils.fromHexString(hexKey);
        // String-->byte[]
        byte[] srcData = paramStr.getBytes(ENCODING);
        // 加密后的数组
        byte[] cipherArray = encrypt_Ecb_Padding(keyData, srcData);
        // byte[]-->hexString
        cipherText = ByteUtils.toHexString(cipherArray);
        return cipherText;
        }

    /**
     * sm4加密
     * @explain 加密模式：ECB
     *          密文长度不固定，会随着被加密字符串长度的变化而变化
     * @param paramStr
     *            待加密字符串
     * @return 返回16进制的加密字符串
     * @throws Exception
     */
    public static String encryptEcb( String paramStr) throws Exception {
        return encryptEcb(sm4Key, paramStr);

    }


    /**
 * 加密模式之Ecb
 * @explain
 * @param key
 * @param data
 * @return
 * @throws Exception
 */
public static byte[] encrypt_Ecb_Padding(byte[] key, byte[] data) throws Exception {
        Cipher cipher = generateEcbCipher(ALGORITHM_NAME_ECB_PADDING, Cipher.ENCRYPT_MODE, key);
        return cipher.doFinal(data);
        }
/**
 * sm4解密
 * @explain 解密模式：采用ECB
 * @param hexKey
 *            16进制密钥
 * @param cipherText
 *            16进制的加密字符串（忽略大小写）
 * @return 解密后的字符串
 * @throws Exception
 */
public static String decryptEcb(String hexKey, String cipherText) throws Exception {
        // 用于接收解密后的字符串
        String decryptStr = "";
        // hexString-->byte[]
        byte[] keyData = ByteUtils.fromHexString(hexKey);
        // hexString-->byte[]
        byte[] cipherData = ByteUtils.fromHexString(cipherText);
        // 解密
        byte[] srcData = decrypt_Ecb_Padding(keyData, cipherData);
        // byte[]-->String
        decryptStr = new String(srcData, ENCODING);
        return decryptStr;
        }
    /**
     * sm4解密
     * @explain 解密模式：采用ECB
     * @param cipherText
     *            16进制的加密字符串（忽略大小写）
     * @return 解密后的字符串
     * @throws Exception
     */
    public static String decryptEcb( String cipherText) throws Exception {

        return decryptEcb(sm4Key,cipherText);
    }
/**
 * 解密
 * @explain
 * @param key
 * @param cipherText
 * @return
 * @throws Exception
 */
public static byte[] decrypt_Ecb_Padding(byte[] key, byte[] cipherText) throws Exception {
        Cipher cipher = generateEcbCipher(ALGORITHM_NAME_ECB_PADDING, Cipher.DECRYPT_MODE, key);
        return cipher.doFinal(cipherText);
        }

/**
 * 校验加密前后的字符串是否为同一数据
 * @explain
 * @param hexKey
 *            16进制密钥（忽略大小写）
 * @param cipherText
 *            16进制加密后的字符串
 * @param paramStr
 *            加密前的字符串
 * @return 是否为同一数据
 * @throws Exception
 */
public static boolean verifyEcb(String hexKey, String cipherText, String paramStr) throws Exception {
        // 用于接收校验结果
        boolean flag = false;
        // hexString-->byte[]
        byte[] keyData = ByteUtils.fromHexString(hexKey);
        // 将16进制字符串转换成数组
        byte[] cipherData = ByteUtils.fromHexString(cipherText);
        // 解密
        byte[] decryptData = decrypt_Ecb_Padding(keyData, cipherData);
        // 将原字符串转换成byte[]
        byte[] srcData = paramStr.getBytes(ENCODING);
        // 判断2个数组是否一致
        flag = Arrays.equals(decryptData, srcData);
        return flag;
        }

    /**
     * 校验加密前后的字符串是否为同一数据
     * @explain
     * @param cipherText
     *            16进制加密后的字符串
     * @param paramStr
     *            加密前的字符串
     * @return 是否为同一数据
     * @throws Exception
     */
    public static boolean verifyEcb( String cipherText, String paramStr) throws Exception {

        return verifyEcb(sm4Key, cipherText, paramStr);
    }

public static void main(String[] args) {
        try {
            String json = "410926";
            //498aa7f8346f78a64a864c3857c7529f
            //bc21195adc9afd0596befeb576428c801fa63bd4ec909be65ea0eecf677e2b86
            // 自定义的32位16进制密钥
            // String key = "86C63180C2806ED1F47B859DE501215B";
            String cipher = Sm4Util.encryptEcb(json);
            System.out.println(cipher);//
            System.out.println(cipher.length());
            System.out.println(Sm4Util.verifyEcb(cipher, json));// true
            json = Sm4Util.decryptEcb(cipher);
            System.out.println(json);
        } catch (Exception e) {
        e.printStackTrace();
        }
        }
}
